The reader initializes the conversation. The RF subject is activated, and several minimal amount commands are exchanged to detect a suitable card. 1x GND 3V3 (P2 with two pins two.54mm) connector can be used to electricity externally the WCH CH569 MCU (it is usually recommended to remove the P4/SHUNT in https://andretkdav.blog-gold.com/41708945/indicators-on-hydrabus-you-should-know